How do you find KF constant?
Divide the freezing point depression by the molal concentration so you have: Kf = delta Tf / cm. Insert the values for delta Tf and cm. For instance, if you have a solution with a molality of 0.455 which freezes at 3.17 degrees Celsius, then Kf would equal 3.17 divided by 0.455 or 6.96 degrees Celsius.
What is the kf value of acetic acid?
3.90 °C· kg/mol
Calculations for Part 1 The density of acetic acid is 1.049 g/mL and Kf (acetic acid) = 3.90 °C· kg/mol The density of the unknown is 0.791 g/mL.
Is KB and KF the same?
Kf is the depression in freezing point produced by 1 molal solution of a nonvolatile solute while Kb is the elevation in boiling point produced by 1 molal solution of a nonvolatile solute.
What is the value of the molal freezing point depression constant for acetic acid?
Note that the molal freezing point depression constant, Kf, has a specific value depending on the identity of the solvent….
| solvent | normal freezing point, oC | Kb, oC m-1 |
|---|---|---|
| water | 0.0 | 1.86 |
| acetic acid | 16.6 | 3.9 |
| benzene | 5.5 | 5.12 |
| chloroform | -63.5 | 4.68 |
How does KF relate to KB?
How does Kf relate to Kb? Kf > Kb (fill in the blank) The freezing point constant is always greater. 6. A solution of 58.5 grams of NaCl in 1,000 grams of water is made.
Are the values of KF and KB dependent on the identity of the solvent the solute or both explain?
The value of Kb or Kf depends only on the type of solvent & not solute dissolved in it.
What is KF in fatigue?
The fatigue stress concentration factor (Kf) can be defined from the ratio of fatigue strength of the smooth member to that of the notched member; it is also often referred to as the fatigue notch factor [9].
What is the freezing point of glacial acetic acid?
61.88°F (16.6°C)Acetic acid / Melting point
What is KF in chemistry solubility?
The equilibrium constant for the formation of the complex ion is the formation constant (Kf).
How do you find the freezing point of KF?
The freezing point depression ∆T = KF·m where KF is the molal freezing point depression constant and m is the molality of the solute. Rearrangement gives: mol solute = (m) x (kg solvent) where kg of solvent is the mass of the solvent (lauric acid) in the mixture. This gives the moles of the solute.
What does KF depends on?
How to find the average K F of lauric acid?
A veraging the freezing point depression constant from the two impure samples allows one to find the average K f of lauric acid. 1. Attach the temperature probe to CH1 on the Lab Pro interface, & connect the interface to the computer. Start the Logger Pro software & open the appropriate files so the title of the 2.
What is the structure of lauric acid?
Lauric Acid is a saturated medium-chain fatty acid with a 12- carbon backbone. Lauric acid is found naturally in various plant and animal fats and oils, and is a major component of coconut oil and palm kernel oil. NCI Thesaurus (NCIt) Lauric acid is a white solid with a slight odor of bay oil.
What is the cryoscopy constant of lauric acid?
Its cryoscopic constant is 3.9°C·kg/mol. By melting lauric acid with the unknown substance, allowing it to cool, and recording the temperature at which the mixture freezes, the molar mass of the unknown compound may be determined.
Why is lauric acid used in molar mass determination?
The choice of lauric acid is convenient because the melting point of the pure compound is relatively high (43.8°C). Its cryoscopic constant is 3.9°C·kg/mol. By melting lauric acid with the unknown substance, allowing it to cool, and recording the temperature at which the mixture freezes, the molar mass of the unknown compound may be determined.